Mighty ... downsizing never hurts to try. A longer rod may be needed, or even braid (with or w/o a leader) .. to get a good hookset from a distance. You might even want to try a Roadrunner in 1/16oz.
They could very well have been "just nipping it" ... they could have recently fed, and just weren't interested in a large bait - but, couldn't pass up a "taste test" . Could have been the Barometric Pressure was higher, too. There's always lots of reasons why they act the way they do ... it's just hard, sometimes, for us to figure out "why". Downsizing never hurts, and is usually effective when they are "just nipping" a larger bait. Even when they are still "just nipping" the smaller bait, it's still more likely that they will have the bait deeper in their mouth ... when you see/feel the strike. You might even want to try a small float, when they're that shallow.
... luck2ya ... cp